Spinning objects, such as tops and gyroscopes, have been popular toys for centuries. Because the position and orientation of a spinning object changes slowly so that the outline of the toy appears stationary, while the surface of the object generally moves faster than the eye can resolve, such toys have an intriguing appearance. The visual appeal of such toys is compounded by the fact that well-designed tops and gyroscopes spin for long periods of time.
It is a commonly observed phenomena that when a coin is rolled on a flat horizontal surface, the path of its contact with the horizontal surface will be a spiral of decreasing radius. As the radius of the spiral approaches the radius of the coin, the rolling motion appears to become a spinning motion. As the coin loses energy to friction/vibration during its spinning/rolling, the angle of inclination of the coin approaches zero.
Similarly, if the coin is spun on a horizontal surface about a vertical axis orthogonal to the axis of cylindrical symmetry of the coin, as the coin loses energy to friction/vibration its angle of inclination again approaches zero, and its path on the horizontal surface describes a spiral with a radius that increases towards the radius of the coin. In the present specification the motion of the coin when the radius of the spiral path is on the order of the radius of the coin will be termed "spolling," and the radius of the near-circular path of contact between the coin and the surface on which it spolls will be termed the "radius of spolling."
A recently developed amusement device based on the spolling motion of coins is the Spin Bank.TM., distributed by WACO Products Corporation of Pine Brook, N.J. As shown in FIG. 1, the Spin Bank (5) has roughly an hour-glass shape. At the top surface (10) of the Spin Bank (5) is a slot (15) through which a coin (20) may be inserted. The slot (15) has a pair of spring-biased metal plates (17) projecting therein, and insertion of the lower half of the coin (20) through the slot (15) forces the plates (17) to separate. Then, as the upper half of the coin (120) passes through the slot, the plates (17) move towards each other due to the biasing of the springs (not shown). The front edges (18) of the plates (17) are parallel to each other and at an oblique angle to the longitudinal axis of the slot (15), so a rotation about a vertical axis is imparted to the coin (20) when it is ejected from the slot (15) by the spring-biased metal plates (17).
A concave mirrored platform (30) with a diameter of approximately 11/4 inches is located at the center plane of the Spin Bank (5) (i.e., where it narrows in width), and when the coin (20) impacts the concave platform (30) it spolls. Often a transverse momentum is imparted to the coin (20), causing the coin (20) to roll off of the concave platform (30). However, if a transverse momentum is not imparted to the coin (20) it will spoll until the radius of the spiral path of contact between the coin (20) and the platform (30) becomes just greater than the radius of the platform (30), at which point the coin (20) will fall from the platform (30). It should be noted that only the initial portion of the spolling of the coin (20) is generally displayed, because the coin (20) usually falls off the platform (30) before its angle of inclination with the horizontal plane becomes small. Because the edges of coins generally have nicks and scratches, and in some cases are serrated (as in the case of the United States ten and twenty-five cent pieces), and because the platform (30) is not especially smooth, energy is lost to friction/vibration fairly rapidly so the spolling motion only lasts a few seconds.
It is therefore an object of the present invention to provide a disc which will spin/roll (i.e., "spoll") on a base for an extended length of time.
It is another object of the present invention to provide a base on which a disc can spin/roll for an extended length of time.
It is another object of the present invention to minimize the energy loss due to friction/vibration of a disc which spins/rolls on a base.
It is another object of the present invention to provide a disc which will reach an angle of low inclination while spolling on a base.
It is therefore another object of the present invention to provide a disc with an edge which minimizes the energy loss due to friction/vibration as the disc spins/rolls on a base.
It is another object of the present invention to enhance the visual effect of the spinning/rolling of a disc on a base.
It is another object of the present invention to provide a base which is relatively immobile as a disc spins/rolls on it.
It is another object of the present invention to provide a base on which a disc can spin/roll without falling off the base.
It is another object of the present invention to provide a disc which will spoll on a base, emitting a tone which rises with pitch as the angle of inclination of the disc becomes low.
The present invention is directed to toy which includes a disc and a base. The disc has a smooth lower edge, the base has a smooth concave upper surface, such that the disc spolls on the base for an extended period of time.
The present invention is also directed to a toy which includes a disc with a smooth lower edge and a base with a concave upper surface. The upper surface of the disc has a tessalated reflective surface, the effective angles of optical orientation of the tiles of the tessalated reflective surface being effectively random.